Conventionally, there has been known a power supply controlling apparatus that communicates with an external device via an ISDN (Integrated Services Digital Network) line (See Japanese Laid-Open Patent Application No. 2007-233596). Further, there has been known a power supply controlling apparatus that includes two serial console ports as illustrated in FIG. 1. FIG. 1 illustrates the configuration of a part of a power supply controlling apparatus.
In FIG. 1, a power supply controlling apparatus 200 includes: a CPU (Central Processing Unit) 201 that controls the whole power supply controlling apparatus; an OS (Operating System) 202 that the CPU 201 activates; a serial console port 203; and a LAN (Local Area Network) connection port 204. The serial console port 203 is a serial console of the OS 202 (e.g. Linux) that operates in the power supply controlling apparatus 200, and connected to an input and output device 205 such as a keyboard and a mouse. The LAN connection port 204 constitutes an Ethernet port for example, and is connected to an external device 206 via a network such as a LAN.
Incidentally, when a modem 207 is connected to the serial console port 203 as illustrated in FIG. 1, and an external device 208 communicates with the power supply controlling apparatus 200 via the modem 207, an IP (Internet Protocol) address corresponding to a connection route of a network 209 and the modem 207 is required for the external device 208. When the connection procedure of the modem 207 and the network 209 is completed, the IP address is decided. Therefore, the external device 208 needs to confirm the IP address beforehand. However, the serial console port 203 is blocked with the modem 207, and hence the external device 208 cannot confirm the IP address. As a result, the power supply controlling apparatus 200 cannot secure a communication route with the external device 208.